A week ago or so I mentioned I had reverse and gears 1 and 2 in my Farmall C. The shifter would not move into 3rd and 4th. I had repeatedly bumped the shifter with my hand with no movement. Tractor had been sitting for several years. Finally found some time to work on it. Someone mentioned to remove the transmission oil filler plug and to try to get some oil sprayed horizontally at the shifting rails. I did remove the plug and bought a can of PB blaster with a permanently attached spray straw. I bent the spray straw at a 90 degree angle near the end. Stuck it into the filler hole in the platform and randomly moved it about. The bend allowed me to spray horizontally at the shifting rails. Within minutes the shifter moved into 3rd and back to 4th with bumps from my hand. Thanks for the advice.